One of the most common fatal diseases is vascular disease, in particular cardiac infarct. This is caused by disease of the coronary arteries (arteriosclerosis). With this disease deposits (arteriosclerotic plaque) cause a “blockage” of the coronary arteries.
If coronary angiography shows serious narrowing (stenosis) of the coronary arteries, which causes angina pectoris, restricts performance and/or threatens the patient, in the majority of cases today a PTCA (Percutaneous Transluminal Coronary Angioplasty) is carried out. To this end the constrictions in the coronary arteries are widened using a so-called “balloon catheter”.
Clinical studies have shown that with this method many patients suffer restenosis, with up to 50% of patients showing some degree of restenosis. The use of stents, which are inserted into the widened constriction, can reduce the restenosis rate by up to 25%.
DCA (Directional Coronary Atherectomy) is available to reduce restenosis further. DCA or “debulking” is a method for reopening stenosed coronary arteries.
The directional atherectomy device is a catheter system with a metal housing, in which the actual cutter is located. The cutter, which comprises a conically ground knife, is connected via a flexible connection to a motor outside the patient. The cutting knife is driven by this motor at a speed of 1500-2000 rpm. A balloon is mounted on one side of the metal housing and there is a window on the contralateral side. During the atherectomy the balloon is inflated and the openings and the knife are thereby pressed into the plaque. The rotating knife can now be pushed forward from outside towards the tip of the atherectomy housing. This causes the plaque to be cut out and the plaque material to be pushed into the tip of the atherectomy device. The balloon is then deflated, the atherectomy device rotated briefly, so that the window points towards another area of plaque and the process is repeated. [Interventional cardiology, angiology and cardiovascular surgery, Prof. V. Hombach, Schattauer Verlag Stuttgart, pages 111-115]
A device for DCA is for example disclosed in U.S. Pat. No. 5,895,402. The product Artherocath GTO from Guidant is known.